The invention relates to an internal combustion engine with a variable volume combustion chamber and comprising an exhaust gas turbocharger with a turbine wheel of a design capable of generating a high engine braking torque with relatively low thermal loads.
The publication on which the preamble is based, DE 101 52 804 A1, describes an internal combustion engine whose exhaust gas turbocharger has a two-inlet passage turbine with an asymmetric turbine housing. The two inlet passages of the turbine are dimensioned such that the emission of pollutants and the fuel consumption of the internal combustion engine are reduced, giving the internal combustion engine a good exhaust emission behavior.
A precondition for the good exhaust emission behavior of the internal combustion engine is a different dimensioning of the two inlet passages, so that the turbine has one inlet passage with a larger effective annular nozzle structure and hence a larger flow cross section, and one inlet passage with a smaller effective annular nozzle structure and hence a smaller flow cross section.
As a result of the different dimensioning of the inlet passages of the turbine, the exhaust gas turbocharger can be employed for an engine braking mode of the internal combustion engine in such a way that when the exhaust gas turbo-charger is used as an engine brake, the inlet passage with the smaller effective annular nozzle is used to back up the air.
It is the object of the present invention to provide an internal combustion engine with an exhaust gas turbocharger which can generate the high braking powers needed for the engine braking mode in a suitable relationship to the speed of the engine predominantly required for the motoring mode with relatively low thermal loads.